The present invention relates to a digital map display zooming method, a digital map display zooming device and a storage medium for storing a digital map display zooming program, which are for enlarging and reducing a displayed portion of a digital map as map information in digital form within a display screen.
Digital maps as map information in digital form are maps put into electronic form so as to be handled on the display screen of a computer such as a portable computer etc. This kind of digital map is referred to as an electronic map or map software, where maps can be displayed on a display screen.
With this kind of digital map, a map is displayed on, for example, the display screen of a portable computer so that an operation such that a target is set on the map can be carried out, with these digital maps being applied to car navigation systems etc. in recent years.
Incidentally, related art operation for enlarging or reducing the displayed portion of the digital map within the display screen is carried out by a user operating prescribed buttons.
However, with this kind of operation for enlarging or reducing the displayed portion of the digital map, the displayed portion of the digital map can only be enlarged or reduced in an intermittent manner on certain scales of, for example, about four steps. The displayed portion of the digital map therefore cannot be displayed at a scale on which the user wishes to set.
It is therefore an object of the present invention to solve the aforementioned problem to provide a digital map display zooming method, a digital map display zooming device and a storage medium for storing a digital map display zooming program which are capable of easily displaying the displayed portion at an arbitrary rate of enlargement by a user continuously enlarging or reducing the displayed portion of the digital map while watching the display screen.